Green Bay - If rookie Jerron McMillian once appeared to have an iron-clad grip on a Green Bay Packers' safety job, he doesn't anymore.

M.D. Jennings split time with McMillian opposite Morgan Burnett in sub packages against Houston and is scheduled to get substantial action Sunday in St. Louis.

"Just making sure we're getting the best guy out there and what we want out of that position," safeties coach Darren Perry said Friday. "They're both young and still learning. Until one guy just kind of nails it down we'll keep rolling them in."

Jennings, a second-year free agent from Arkansas State, was ahead of McMillian until he was pulled 15 snaps into the opener against San Francisco after he blew a coverage on a touchdown pass to Randy Moss and missed the tackle on a long run by Frank Gore.

From Game 2 to Game 5, McMillian played 234 snaps whereas Jennings hardly played with 13.

In Houston, however, Jennings made the most of his 28-26 edge in plays by making eight tackles compared to McMillian's two.

McMillian, a fourth-round draft choice from Maine, made some mistakes that proved costly the week before in Indianapolis.

"We've just got to get him consistent," Perry said, referring to McMillian. "As a young player, there will be some growing pains and some mistakes.

"He brings a toughness that you like. He's got some football savvy and instincts, and he has made some plays for us on third down. That's one of the reasons we played him."

"He's a heady player and is rarely out of position back there," Perry said, referring to Jennings. "He's a good communicator. He's also got good ball skills. He's a lanky-looking guy that is faster than I think most people think. He's pretty good in space getting ball carriers down."

Ready to roll: Before the 2011 draft, an AFC special-teams coach said running back Johnny White of North Carolina was one of the best punt-team gunners available.

"He can catch the (expletive) out of the ball and he's a damn good special-teams player," an NFC scout said at the time. "If you're the Green Bay Packers, he's a damn good third-round or early fourth-round pick."

Awarded to the Packers off waivers from Buffalo on Monday, White figures to be active and playing special teams against the Rams.

"He can be a contributor because he's very bright," coordinator Shawn Slocum said. "He played gunner in Buffalo. He also has played fullback, wing and covered kickoffs inside and outside. He's been on punt returns. He's a kickoff returner. Done it all."

White (5-10, 210) scored 24 on the Wonderlic intelligence test and ran the 40 in 4.53 seconds. He played wide receiver and cornerback in college before switching to running back in late 2008.

In Buffalo, White rushed 36 times for a paltry 67 yards (1.9) in two exhibition seasons.

“He’s a tough, downhill runner,” an AFC scout said in April 2011. “Between the tackles. And he has good speed.”

Slocum said linebacker Brad Jones would return to his left guard spot on the punt team. Because of injury, Jones moved to wing on the punt that was blocked by the Texans because of mistakes made by backup left guard Tom Crabtree and left tackle Rob Francois.

White could take some of Jones' load on special teams because Jones might have to play the entire game on defense in the wake of D.J. Smith's season-ending knee injury.

White will become an exclusive-rights free agent after the season with the expiration of his one-year, $465,000 contract that was assumed by Green Bay.

Coach Mike McCarthy said he was hopeful Jennings would return next week.

Cornerback Davon House said he has tested his damaged left shoulder every way possible short of live tackling and had experienced no pain.

Linebacker Frank Zombo took a full load on the scout-team defense and appeared to have no problems with the hamstring injury that has bothered him for months.

"For missing as much time as he did I was concerned about his conditioning," defensive coordinator Dom Capers said. "But he kept himself in good shape."

In St. Louis, the Rams have an enormous problem at left tackle opposite Clay Matthews. Starter Rodger Saffold (knee) is out and backup Wayne Hunter (back), who struggled mightily as the starter the last four games, didn't even attend practice all week and is questionable.

It appears as if the starter will be Joe Barksdale (6-4½, 329), who was claimed off waivers from Oakland Sept. 27.

Barksdale, a third-round draft choice in 2011, played 152 snaps for Oakland as a rookie. He has enormous arms (36 inches) but is slow and not very tough.

Go fast: The Packers have run 110 snaps without using a huddle, or 28.2% of their plays. According to STATs, only five teams have used the no-huddle more, led by Miami and coach Joe Philbin at 58.6%.

The Packers have averaged 6.85 yards in no-huddle. Denver leads the no-huddle offenses with an 8.17 average.

Good job: Center Evan Dietrich-Smith debuted as a sixth offensive lineman with four snaps against Houston.

“He moved his guy,” O-line coach James Campen said. “He’s a strong kid and we had a need there.”

Guard Greg Van Roten, promoted from the practice squad last week, signed a three-year, $1.44 million minimum deal.

“He has improved a lot,” said Campen. “He’s smart now. Calls and adjustments. You’re not going to stump him very often.”

A graduate of Penn, Van Roten scored 34 on the Wonderlic.

Waiting, watching: Dave McGinnis, the Rams’ assistant head coach, said it appears to him that the Packers don’t really worry about who is playing on the opposing defense.

“It’s a pretty well-oiled machine when you watch it and it really gets going,” McGinnis said Thursday. “Plus the fact those receivers are interchangeable. You don’t get a bead on where a receiver lines up. They line up everywhere. They all can play all the positions.

“They understand it and that is what gives them a great opportunity to run as many plays as they do because it’s at-the-line and quarterback-driven . . . they’ve won a lot of games with this group for a reason. They’re really good at what they do.”

About Bob McGinn

Bob McGinn is a beat writer and columnist covering the Green Bay Packers. A six-time Wisconsin state sportswriter of the year, he won the Dick McCann Memorial Award in 2011 for long and distinguished reporting on pro football.